


Twice The Experiments, Twice The Fun

by TellTaleKael



Series: Error’s Dolls [2]
Category: Undertale (Video Game)
Genre: Bottom Nightmare, Courtesy Of Error, Cross Sans/Nightmare Sans, Error Is Naughty, Forced Sex, M/M, Masturbation, Mind Control, Rape/Non-con Elements, Top Cross, Vaginal Sex, Voyeurism, almost?
Language: English
Status: Completed
Published: 2021-02-06
Updated: 2021-02-06
Packaged: 2021-03-17 18:07:05
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 1,094
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29229711
Author URL: https://archiveofourown.org/users/TellTaleKael/pseuds/TellTaleKael
Summary: Two weeks. It had been two weeks since Error had used his dolls, and he couldn’t wait any longer.
Relationships: Sans/Sans (Undertale)
Series: Error’s Dolls [2]
Series URL: https://archiveofourown.org/series/2146278
Comments: 6
Kudos: 142





	Twice The Experiments, Twice The Fun

**Author's Note:**

> Please note this contains non-con! Don’t read if you are not in a place to do so right now, I promise I don’t mind!

Two weeks. That’s how long Error managed to keep away from the dolls. The special ones he had made. Two weeks since he had felt pleasure without pain.

He wanted more.

Lowering the Cross doll down from where it hung on a string, Error took it in hand carefully. Its button eyes looked back at him blankly. He wanted to see Cross’ reactions this time, not just feel them. With hands that trembled in excitement, he opened a portal to peer in on Cross.

The monochromatic skeleton wasn’t alone, like Error expected him to be. No, he was in Nightmare’s study... with Nightmare. 

Error huffed. As much fun as it would be to mess with Cross in front of Nightmare again, he was a little concerned that their leader would be able to track the origin of the strange phenomenon back to Error’s magic, and he wasn’t quite sure he wanted to give away the game just yet.

Resigned, he looked at the doll. There was no way he could go through with his plan without Nightmare noticing. Unless...

Error reached a hand out, lowering another doll to rest in his palm. He had made a point of creating as many of them as he could, harvesting code from all over the multiverse. But did he dare use this one? The black button eye of the Nightmare doll seemed to peer directly at him. Technically, Error couldn’t die. But Nightmare could probably make him wish he could, if so inclined. Heat began to build low in his gut.

As long as he kept Nightmare sufficiently distracted, he should be able to get away with this.

***

“-and with Dream hiding in Haventale, I can’t reach him,” Nightmare said, crossing his arms as he leaned against his desk. “So now would be the best moment to take time to handle any pressing matters.”

Cross fought not to blush, standing at attention. He shook his skull, face dipping down further in his scarf. “I’m not in heat. I’m not even anywhere close to my heat. That’s not what happened.” He couldn’t say for certain what had happened, but he knew what it wasn’t, at least. Those phantom touches had not been anything he had felt before, and certainly weren’t the clenching aches of heat. 

Nightmare studied him intently with his good eyelight. “I’m not a liability,” Cross insisted.

“That’s not why I brought up my concerns-“ Nightmare began, before pausing. He tilted his skull, as if trying to listen to something.

A familiar tickling sensation assaulted Cross’ spine. _Not again!_ He opened his mouth to warn Nightmare, but it felt as if something forced it shut again, teeth clanking together. He lurched forward, propelled by some unseen force, crowding Nightmare against the desk, arms braced on either side of him. He couldn’t even apologize, sockets widening. They seemed to be the only body part he was in control of. 

Shakily, he leaned in, teeth clanking against Nightmare’s awkwardly. There was a pause, before Nightmare moved back against him, teeth parting. Tongues met, slick and warm, purple against cyan. Nightmare made a muffled sound, arms coming up to wrap around Cross. Something soft pressed against his front, warm pressure against his ribs through their clothes. 

The kiss ended, and Cross stumbled back slightly, legs moving of their own accord. His eyelights snapped down, taking in the sudden curves visible through Nightmare’s clothes. His own ecto snapped into place, hard and hot, shorts suddenly very, very tight. He reached out, curling his phalanges in Nightmare’s hoodie. With a mighty pull, he ripped the fabric apart, allowing full, soft breasts to bounce free. A startled sound slipped out of Nightmare, but when Cross looked up in concern, Nightmare reached out, yanking Cross’ shorts down. 

Curved and dripping, Cross’ cock rose from his pelvis. One of Nightmare’s tentacles surged forward, curling around heated flesh, rubbing and squeezing in tandem. While it worked him over, the rest of the tentacles set about ripping Nightmare’s shorts off of him, revealing that his ecto went all the way to his knees, with a dripping pussy between his thighs, glistening and ready. 

The heady scent of sex filled the room, heavy on each breath Cross inhaled. He had never imagined that he would get to see Nightmare like this, to feel the softness of his breasts as he took them in hand. Pleasure and desire filled his head, with only a nagging feeling left in the back of his mind that things weren’t right. 

Nightmare’s tentacle released him, and Cross took a step forward. He lifted Nightmare up, setting him onto the desk, hips tilted up off the edge. It only seemed natural for him to reach down and line his cock up with Nightmare’s entrance, the head catching easily. It only took a few rolls of his hips until he was fully seated into the wet warmth of his boss’ innermost depths. 

He wasted no time, rocking his hips, setting a quick, sharp pace. Pleasure built in his pelvis, racing up along his spine, heated breaths coming out in pants. Nightmare’s moans were like music, growing higher in pitch when Cross spared a hand to reach between them and pinch his clit. 

The haze grew stronger the closer Cross got to the edge. His movements grew sloppier, more desperate. He swallowed Nightmare’s moan in a kiss as they both came, and explosion of pleasure and completeness that crashed over them. 

They remained there, panting into one another, still locked together, until the haze lifted, and suddenly reality hit them like a ton of bricks.

“What the _fuck_?!”

***

Error strung the dolls up, flopping back and shoving his hand into his shorts. It took only a few strokes for him to spill into his palm with a choked cry. The image in the portal faded, though he knew the sight would still remain in his memory for a long time to come. 

Tying gags around the mouths of the dolls had been a stroke of genius, to prevent the two from speaking while he controlled their movements. He had to admit, he would have never expected Nightmare to form such a well-endowed body of curves, but Cross certainly hadn’t seemed to mind. Error chuckled dryly, trying to imagine the conversation the two were having. It was honestly past time they succumbed to that obvious tension they had and fucked about it already. What he did was just... help them along.

That’s what he would say if- stars forbid- Nightmare ever found out who was responsible.


End file.
